Orthopedics

Feature Articles 

Application of Locking Plate in Long-Bone Atrophic Nonunion Following External Fixation

Si-guo Sun, MD; Yong Zhang, MD; Lian-he Zheng, MD; Jun Li, MD; De-gang Fan, MD; Bao-an Ma, MD

Abstract

The treatment of atrophic fracture nonunion continues to represent a therapeutic challenge. Large segmental osteopenia is often seen in patients who received uniplanar or hybrid external fixators as the definitive method of fixation for high-energy fractures, and this adds more difficulties to the treatment of fracture nonunion. This retrospective study was designed to assess the outcome of locking compression plating with autologous bone grafting in patients with long-bone atrophic nonunion following external fixation.

From January 2004 to December 2009, a series of consecutive patients with atrophic nonunion of the long bone following external fixation were treated with this method in our institution. The clinical outcomes and complications of these patients were retrospectively analyzed. Twenty-seven patients with 28 fracture nonunions were involved in this study. Mean follow-up was 14.2±3.4 months. Bony union was achieved in all 27 patients within a mean 18.6±4.8 weeks after revision surgery. Two patients developed superficial wound infections. No deep infections were found, and no implant failure was seen. Three patients reported minor pain in the donor site of the bone graft, and no other donor site complications were found.

Revision osteosynthesis of long-bone atrophic nonunion following external fixation by locking compression plating with autologous iliac crest bone grafting represents a safe and efficacious modality for the treatment of these challenging conditions.

External fixation is often used in high-energy polytrauma patients who may have open wounds, massive soft tissue injury, bony comminution, or bone loss unsuitable for acute internal fixation. Such patients are more likely to develop atrophic nonunion due to severe devascularization of the fractured bone and poor quality of soft tissue bed compared to those patients with low-energy fractures. Furthermore, large segmental osteopenia is often seen in patients who received uniplanar or hybrid external fixators as the definitive method of fixation because of the stress shielding effect of the fixator and disuse of the limbs. These patients become a therapeutic challenge if they develop fracture nonunion due to the poor quality of the bone and surrounding soft tissue.

Locking plates have been used successfully in the treatment of osteoporotic fractures in which bone quality was poor.1,2 The locking compression plate provides compression while maintaining fixation of poor-quality bone. It also requires minimal stripping of soft tissue surrounding the fracture site since it was placed in the periosteum. The locking compression plate has recently been proven successful in treatment of atrophic nonunions.3,4 To advocate the use of this technique, further evidence is needed.

This retrospective study was designed to assess the outcome of locking compression plating with autologous bone grafting in patients with long-bone atrophic nonunions following external fixation.

A series of consecutive patients treated with locking compression plating and autologous bone grafting for long-bone fracture nonunion following external fixation in our orthopedic department between January 2004 and December 2009 were retrospectively analyzed. Patients were included if they received external fixation as the definitive treatment for fracture and then developed nonunion that was treated with locking compression plating and autologous bone grafting. Exclusion criteria for this study were pathologic fracture, severe systemic illness (active cancer, chemotherapy, insulin-dependent diabetes, renal failure, hemophilia, or a medical contraindication for surgery), open growth plates, age older than 65 years, bone defect >5 cm, and infected nonunion. The presence of infection was excluded by preoperative analysis of systemic infection parameters (white blood count, sedimentation rate, C-reactive protein) and by culture and histopathologic analysis of tissue samples from the resected nonunion. All patients were treated for nonunion by the same team of surgeons (S.S., Y.Z., L.Z., J.L., D.F., B.M.), who followed similar operative and postoperative procedures. This study was approved by the…

Abstract

The treatment of atrophic fracture nonunion continues to represent a therapeutic challenge. Large segmental osteopenia is often seen in patients who received uniplanar or hybrid external fixators as the definitive method of fixation for high-energy fractures, and this adds more difficulties to the treatment of fracture nonunion. This retrospective study was designed to assess the outcome of locking compression plating with autologous bone grafting in patients with long-bone atrophic nonunion following external fixation.

From January 2004 to December 2009, a series of consecutive patients with atrophic nonunion of the long bone following external fixation were treated with this method in our institution. The clinical outcomes and complications of these patients were retrospectively analyzed. Twenty-seven patients with 28 fracture nonunions were involved in this study. Mean follow-up was 14.2±3.4 months. Bony union was achieved in all 27 patients within a mean 18.6±4.8 weeks after revision surgery. Two patients developed superficial wound infections. No deep infections were found, and no implant failure was seen. Three patients reported minor pain in the donor site of the bone graft, and no other donor site complications were found.

Revision osteosynthesis of long-bone atrophic nonunion following external fixation by locking compression plating with autologous iliac crest bone grafting represents a safe and efficacious modality for the treatment of these challenging conditions.

External fixation is often used in high-energy polytrauma patients who may have open wounds, massive soft tissue injury, bony comminution, or bone loss unsuitable for acute internal fixation. Such patients are more likely to develop atrophic nonunion due to severe devascularization of the fractured bone and poor quality of soft tissue bed compared to those patients with low-energy fractures. Furthermore, large segmental osteopenia is often seen in patients who received uniplanar or hybrid external fixators as the definitive method of fixation because of the stress shielding effect of the fixator and disuse of the limbs. These patients become a therapeutic challenge if they develop fracture nonunion due to the poor quality of the bone and surrounding soft tissue.

Locking plates have been used successfully in the treatment of osteoporotic fractures in which bone quality was poor.1,2 The locking compression plate provides compression while maintaining fixation of poor-quality bone. It also requires minimal stripping of soft tissue surrounding the fracture site since it was placed in the periosteum. The locking compression plate has recently been proven successful in treatment of atrophic nonunions.3,4 To advocate the use of this technique, further evidence is needed.

This retrospective study was designed to assess the outcome of locking compression plating with autologous bone grafting in patients with long-bone atrophic nonunions following external fixation.

Materials and Methods

A series of consecutive patients treated with locking compression plating and autologous bone grafting for long-bone fracture nonunion following external fixation in our orthopedic department between January 2004 and December 2009 were retrospectively analyzed. Patients were included if they received external fixation as the definitive treatment for fracture and then developed nonunion that was treated with locking compression plating and autologous bone grafting. Exclusion criteria for this study were pathologic fracture, severe systemic illness (active cancer, chemotherapy, insulin-dependent diabetes, renal failure, hemophilia, or a medical contraindication for surgery), open growth plates, age older than 65 years, bone defect >5 cm, and infected nonunion. The presence of infection was excluded by preoperative analysis of systemic infection parameters (white blood count, sedimentation rate, C-reactive protein) and by culture and histopathologic analysis of tissue samples from the resected nonunion. All patients were treated for nonunion by the same team of surgeons (S.S., Y.Z., L.Z., J.L., D.F., B.M.), who followed similar operative and postoperative procedures. This study was approved by the hospital ethics committee, and all patients gave their informed consent before inclusion in the study.

Surgical Technique

The external fixators were removed, pin tracks scraped, and limbs placed in braces for 7 to 14 days. Oral antibiotics were administered for 3 to 5 days if a pin-track infection was found, and surgery was delayed until the pin-track infection was resolved. The least amount of soft tissue stripping necessary was used to expose the nonunion sites. All fibrous and scar tissue was removed from around the nonunion site, including the entire pseudocapsule. The fibrous covering over the intramedullary canal on both sides was removed using curettes and drills until a well-vascularized bone bed was observed. The autologous bone graft taken from iliac crest was placed in the fracture site. Osteothesis was performed with a locking compression plate (Weigal Orthopaedic Device Co Ltd, Yantai, Shandong, China) after anatomical reduction was achieved. Compression in the fracture site was always performed when possible (Figure).

Figure A: Double bone fractures Figure B: After 6 months’ fixation Figure C: Revision surgery was performed Figure D: 18 weeks after revision surgery Figure E: 28 weeks after revision surgery
Figure: Double bone fractures in the left forearm of a 41-year-old man were treated with external fixation (A). After 6 months’ fixation, atrophic nonunions in the ulna and radius were identified (B). Revision surgery was performed with locking compression plating and autologous bone grafting (C). Bony union was achieved 18 weeks after revision surgery (D). Bone remodeling can be seen 28 weeks after revision surgery (E).

No external immobilization was necessary. On postoperative day 1, gentle activity was initiated. Aggressive range of motion exercises and partial weight bearing was started as soon as tolerated by the patient. Full weight bearing was permitted only after clinicoradiological evidence of union. Union was defined as the absence of pain and motion at the fracture site and bridging bone across 3 cortices on plain radiographs. Patients were followed up at monthly intervals for the first 6 months postoperatively and then every 2 months for up to 1 year to assess progress of union and possible complications.

Results

Twenty-seven patients with 28 fracture nonunions were enrolled in this study (Table). Mean time between primary fixation and revision surgery was 9.3±2.8 months. Mean follow-up after revision surgery was 14.2±3.4 months.

Table

Bony union was achieved in all 28 nonunions (27 patients) 18.6±4.8 weeks after revision surgery (Figure). Two tibial diaphyseal nonunions showed minimal callus on radiographs 24 weeks postoperatively and were further treated with low-intensity pulsed ultrasound. Bony union was achieved at 32 and 36 weeks, respectively. Both of the patients were active smokers.

All patients reported significant improvement in pain and function of limbs. Two patients developed superficial wound infections that resolved with debridement and oral antibiotics. No deep infection was found. Three patients reported minor donor site pain. No other complications (such as neurovascular injury, fracture including avulsion of the anterior superior iliac spine, infection, hematoma, herniation of abdominal contents, and gait disturbance) were found.

Discussion

Approximately 5% to 10% of fractures develop nonunions and/or delayed unions, which result in a large burden for patients and society.5 The management of fracture nonunion remains challenging to most surgeons. For those atrophic nonunions with bone defection and poor bone quality, the treatment becomes more difficult. We treated 27 patients with 28 long-bone atrophic nonunions with locking compression plating and autologous bone grafting, and achieved good results with 100% union rate and functional improvement.

The cause of fracture nonunion is usually unknown. The known reasons of impaired unions include complications with operative and nonoperative interventions, inadequate mobilization of the fracture, distraction of fracture fragments by fixation devices or traction, repeated manipulations or excessive early motion of a fracture, excessive periosteal stripping, and damage to other soft tissues during operative exposure. Other risks for impaired fracture healing include smoking, diabetes, and the location of the injury.6 In our series of patients, devascularization of the fractured bone and poor quality of the soft tissue due to high-energy trauma could contribute to fracture nonunions. Improper use of the external fixator intra- and postoperatively may also contribute to fracture nonunions.

Surgical techniques for revision of fracture nonunions include intramedullary nailing and plating and external fixating. Conflicting results have been reported for both techniques. The locking compression plate was designed to overcome the pitfalls of conventional plates, particularly when dealing with difficult problems such as comminuted, metaphyseal, and osteoporotic fractures. Its advantages have been demonstrated by several studies.2,7,8 It has also been successfully used in the treatment of fracture nonunions.3,4 In this study, the locking compression plate provided enhanced stability for osteopenic bone, and no implant failure or pullout was found postoperatively. Additionally, the locking compression plate was placed on the periosteum, which did not demand wide stripping of soft tissue surrounding the nonunion sites. Therefore, the vascular supply to the nonunion sites was maximally preserved. Twenty-eight nonunions in this study achieved bone in a mean time of 18.264.7 weeks, with a union rate of 100%.

Strategies to bridge bone defects include autologous or allogeneic bone grafts and bone transfer and bone substitute combined with osteogenic stimulators. For short-bone defects, autologous iliac crest bone graft or bone substitute combined with osteogenic stimulators (eg, bone morphogenetic proteins) are the most commonly used techniques. Despite the possibility of donor site complications, autologous iliac crest bone graft provides the quickest and most reliable type of bone graft, and it is held by some authors to be the gold standard for the treatment of short-bone defects.9,10 It also has an economic advantage compared to bone substitute combined with osteogenic stimulators. In our series of patients, only 3 patients reported minor donor site pain. There were no other complications such as neurovascular injury, fracture including avulsion of the anterior superior iliac spine, infection, hematoma, herniation of abdominal contents, and gait disturbance. Careful intraoperative manipulation and harvest of the minimal amount of bone necessary helped to reduce the rate of donor site complications.

Despite excellent and encouraging early results, our study has some limitations. The series includes a relatively small number of patients, and the method was not compared with another method prospectively to investigate if the outcomes are superior.

Conclusion

Locking compression plating with autologous bone grafting for the treatment of long-bone atrophic nonunion following external fixation provides a high union rate and enables initiation of early active unlimited motion. In this study, excellent results were achieved without major complications at short- and mid-term follow-up.

References

  1. Siwach R, Singh R, Rohilla RK, Kadian VS, Sangwan SS, Dhanda M. Internal fixation of proximal humeral fractures with locking proximal humeral plate (LPHP) in elderly patients with osteoporosis [published online ahead of print July 16, 2008]. J Orthop Traumatol. 2008; 9(3):149-153.
  2. Miranda MA. Locking plate technology and its role in osteoporotic fractures. Injury. 2007; 38(Suppl 3):S35-39.
  3. Spitzer AB, Davidovitch RI, Egol KA. Use of a “hybrid” locking plate for complex metaphyseal fractures and nonunions about the humerus [published online ahead of print February 4, 2009]. Injury. 2009; 40(3):240-244.
  4. Khan SA, Shamshery P, Gupta V, Trikha V, Varshney MK, Kumar A. Locking compression plate in long standing clavicular nonunions with poor bone stock. J Trauma. 2008; 64(2):439-441.
  5. Praemer A, Furner S, Rice DP. Musculoskeletal Conditions in the United States. 2nd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 1999.
  6. Einhorn TA. Enhancement of fracture-healing. J Bone Joint Surg Am. 1995; 77(6):940-956.
  7. Biggi F, Di Fabio S, D’Antimo C, Trevisani S. Tibial plateau fractures: internal fixation with locking plates and the MIPO technique. Injury. 2010; 41(11):1178-1182.
  8. Pai HT, Lee YS, Cheng CY. Surgical treatment of midclavicular fractures in the elderly: a comparison of locking and nonlocking plates. Orthopedics. 2009; 32(4). pii: orthosupersite.com/view.asp?rID=38059.
  9. Marino JT, Ziran BH. Use of solid and cancellous autologous bone graft for fractures and nonunions. Orthop Clin North Am. 2010; 41(1):15-26.
  10. Sen MK, Miclau T. Autologous iliac crest bone graft: should it still be the gold standard for treating nonunions? Injury. 2007; 38(Suppl 1):S75-80.

Authors

Drs Sun, Zhang, Zheng, Li, Fan, and Ma are from the Department of Orthopedic Surgery, Tangdu Hospital, the Fourth Military Medical University, Xi’an, Shaanxi Province, PR China.

Drs Sun, Zhang, Zheng, Li, Fan, and Ma have no relevant financial relationships to disclose.

Si-guo Sun, MD, and Yong Zhang, MD, contributed equally to this study.

Correspondence should be addressed to: Bao-an Ma, MD, Department of Orthopedic Surgery, Tangdu Hospital, the Fourth Military Medical University, Xi’an, Shaanxi Province, 710038, PR China (mabaoanfmmu@126.com).

doi: 10.3928/01477447-20110317-12

10.3928/01477447-20110317-12

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